uppy/docs/uploader/xhr.mdx

---
sidebar_position: 5
slug: /xhr-upload
---

import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
import UppyCdnExample from '/src/components/UppyCdnExample';

# XHR

The `@uppy/xhr-upload` plugin is for regular uploads to a HTTP server.

## When should I use it?

:::tip

Not sure which uploader is best for you? Read
“[Choosing the uploader you need](/docs/guides/choosing-uploader)”.

:::

When you have an existing HTTP server and you don’t need Transloadit services or
want to run a [tus][] server. Note that it’s still possible to use [tus][]
without running an extra server by integrating tus into your existing one. For
instance, if you have a Node.js server (or server-side framework like Next.js)
you could integrate [tus-node-server][].

## Install

<Tabs>
  <TabItem value="npm" label="NPM" default>

```shell
npm install @uppy/xhr-upload
```

  </TabItem>

  <TabItem value="yarn" label="Yarn">

```shell
yarn add @uppy/xhr-upload
```

  </TabItem>

  <TabItem value="cdn" label="CDN">
    <UppyCdnExample>
      {`
        import { Uppy, XHRUpload } from "{{UPPY_JS_URL}}"
        new Uppy().use(XHRUpload, { endpoint: 'https://tusd.tusdemo.net/files' })
      `}
    </UppyCdnExample>
  </TabItem>
</Tabs>

## Use

A quick overview of the complete API.

```js {10} showLineNumbers
import Uppy from '@uppy/core';
import Dashboard from '@uppy/dashboard';
import XHR from '@uppy/xhr-upload';

import '@uppy/core/dist/style.min.css';
import '@uppy/dashboard/dist/style.min.css';

new Uppy()
	.use(Dashboard, { inline: true, target: 'body' })
	.use(XHR, { endpoint: 'https://your-domain.com/upload' });
```

## API

### Options

#### `id`

A unique identifier for this plugin (`string`, default: `'XHRUpload'`).

#### `endpoint`

URL of the HTTP server (`string`, default: `null`).

#### `method`

Configures which HTTP method to use for the upload (`string`, default:
`'post'`).

#### `formData`

Configures whether to use a multipart form upload, using [FormData][]
(`boolean`, default: `true`).

This works similarly to using a `<form>` element with an `<input type="file">`
for uploads. When set to `true`, file metadata is also sent to the endpoint as
separate form fields. When set to `false`, only the file contents are sent.

#### `fieldName`

When [`formData`](#formData-true) is set to true, this is used as the form field
name for the file to be uploaded.

It defaults to `'files[]'` if `bundle` option is set to `true`, otherwise it
defaults to `'file'`.

#### `allowedMetaFields`

Pass an array of field names to limit the metadata fields that will be added to
upload.

- Set this to an empty array `[]` to not send any fields.
- Set this to `['name']` to only send the `name` field.
- Set this to `null` (the default) to send _all_ metadata fields.

If the [`formData`](#formData-true) option is set to false, `metaFields` is
ignored.

#### `headers`

An object containing HTTP headers to use for the upload request. Keys are header
names, values are header values.

```js
const headers = {
	authorization: `Bearer ${window.getCurrentUserToken()}`,
};
```

Header values can also be derived from file data by providing a function. The
function receives an [Uppy file][] and must return an object where the keys are
header names, and values are header values.

```js
const headers = (file) => {
	return {
		authorization: `Bearer ${window.getCurrentUserToken()}`,
		expires: file.meta.expires,
	};
};
```

:::note

The function syntax is not available when [`bundle`](#bundle) is set to `true`.

:::

:::note

Failed requests are retried with the same headers. If you want to change the
headers on retry,
[such as refreshing an auth token](#how-can-I-refresh-auth-tokens-after-they-expire),
you can use [`onBeforeRequest`](#onbeforerequest).

:::

#### `bundle`

Send all files in a single multipart request (`boolean`, default: `false`).

All files will be appended to the provided `fieldName` field in the request.

:::caution

When `bundle` is set to `true`:

- [`formData`](#formData-true) must also be set to `true`.
- Uppy won’t be able to bundle remote files (such as Google Drive) and will
  throw an error in this case.
- Only [global uppy metadata](/docs/uppy/#meta) is sent to the endpoint.
  Individual per-file metadata is ignored.

:::

To upload files on different fields, use
[`uppy.setFileState()`](/docs/uppy#uppy-setFileState-fileID-state) to set the
`xhrUpload.fieldName` property on the file:

```js
uppy.setFileState(fileID, {
	xhrUpload: { fieldName: 'pic0' },
});
```

#### `timeout: 30 * 1000`

Abort the connection if no upload progress events have been received for this
milliseconds amount (`number`, default: `30_000`).

Note that unlike the [`XMLHttpRequest.timeout`][xhr.timeout] property, this is a
timer between progress events: the total upload can take longer than this value.
Set to `0` to disable this check.

#### `limit`

The maximum amount of files to upload in parallel (`number`, default: `5`).

#### `responseType`

The response type expected from the server, determining how the `xhr.response`
property should be filled (`string`, default: `'text'`).

The `xhr.response` property can be accessed in a custom
[`getResponseData()`](#getResponseData-responseText-response) callback. This
option sets the [`XMLHttpRequest.responseType`][xhr.responsetype] property. Only
`''`, `'text'`, `'arraybuffer'`, `'blob'` and `'document'` are widely supported
by browsers, so it’s recommended to use one of those.

#### `withCredentials`

Indicates whether cross-site Access-Control requests should be made using
credentials (`boolean`, default: `false`).

#### `onBeforeRequest`

An optional function that will be called before a HTTP request is sent out
(`(xhr: XMLHttpRequest, retryCount: number) => void | Promise<void>`).

#### `shouldRetry`

An optional function called once an error appears and before retrying
(`(xhr: XMLHttpRequesT) => boolean`).

The amount of retries is 3, even if you continue to return `true`. The default
behavior uses
[exponential backoff](https://en.wikipedia.org/wiki/Exponential_backoff) with a
maximum of 3 retries.

#### `onAfterResponse`

An optional function that will be called after a HTTP response has been received
(`(xhr: XMLHttpRequest, retryCount: number) => void | Promise<void>`).

#### `locale: {}`

```js
export default {
	strings: {
		// Shown in the Informer if an upload is being canceled because it stalled for too long.
		timedOut: 'Upload stalled for %{seconds} seconds, aborting.',
	},
};
```

## Frequently Asked Questions

### How can I refresh auth tokens after they expire?

```js
import Uppy from '@uppy/core';
import XHR from '@uppy/xhr-upload';

let token = null;

async function getAuthToken() {
	const res = await fetch('/auth/token');
	const json = await res.json();
	return json.token;
}

new Uppy().use(XHR, {
	endpoint: '<your-endpoint>',
	// Called again for every retry too.
	async onBeforeRequest(xhr) {
		if (!token) {
			token = await getAuthToken();
		}
		xhr.setRequestHeader('Authorization', `Bearer ${token}`);
	},
	async onAfterResponse(xhr) {
		if (xhr.status === 401) {
			token = await getAuthToken();
		}
	},
});
```

### How to send along meta data with the upload?

When using XHRUpload with [`formData: true`](#formData-true), file metadata is
sent along with each upload request. You can set metadata for a file using
[`uppy.setFileMeta(fileID, data)`](/docs/uppy#uppy-setFileMeta-fileID-data), or
for all files simultaneously using
[`uppy.setMeta(data)`](/docs/uppy#uppy-setMeta-data).

It may be useful to set metadata depending on some file properties, such as the
size. You can use the [`file-added`](/docs/uppy/#file-added) event and the
[`uppy.setFileMeta(fileID, data)`](/docs/uppy#uppy-setFileMeta-fileID-data)
method to do this:

```js
uppy.on('file-added', (file) => {
	uppy.setFileMeta(file.id, {
		size: file.size,
	});
});
```

Now, a form field named `size` will be sent along to the
[`endpoint`](#endpoint-39-39) once the upload starts.

By default, all metadata is sent, including Uppy’s default `name` and `type`
metadata. If you do not want the `name` and `type` metadata properties to be
sent to your upload endpoint, you can use the [`metaFields`](#metaFields-null)
option to restrict the field names that should be sent.

```js
uppy.use(XHRUpload, {
	// Only send our own `size` metadata field.
	allowedMetaFields: ['size'],
});
```

### How to upload to a PHP server?

The XHRUpload plugin works similarly to a `<form>` upload. You can use the
`$_FILES` variable on the server to work with uploaded files. See the PHP
documentation on [Handling file uploads][php.file-upload].

The default form field for file uploads is `files[]`, which means you have to
access the `$_FILES` array as described in [Uploading many files][php.multiple]:

```php
<?php
// upload.php
$files = $_FILES['files'];
$file_path = $files['tmp_name'][0]; // temporary upload path of the first file
$file_name = $_POST['name']; // desired name of the file
move_uploaded_file($file_path, './img/' . basename($file_name)); // save the file in `img/`
```

Note how we are using `$_POST['name']` instead of `$my_file['name']`.
`$my_file['name']` has the original name of the file on the user’s device.
`$_POST['name']` has the `name` metadata value for the uploaded file, which can
be edited by the user using the [Dashboard](/docs/dashboard).

Set a custom `fieldName` to make working with the `$_FILES` array a bit less
convoluted:

```js
// app.js
uppy.use(XHRUpload, {
	endpoint: '/upload.php',
	fieldName: 'my_file',
});
```

```php
<?php
// upload.php
$my_file = $_FILES['my_file'];
$file_path = $my_file['tmp_name']; // temporary upload path of the file
$file_name = $_POST['name']; // desired name of the file
move_uploaded_file($file_path, $_SERVER['DOCUMENT_ROOT'] . '/img/' . basename($file_name)); // save the file at `img/FILE_NAME`
```

[formdata]: https://developer.mozilla.org/en-US/docs/Web/API/FormData
[xhr.timeout]:
	https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/timeout
[xhr.responsetype]:
	https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/responseType
[uppy file]: /docs/uppy#working-with-uppy-files
[php.file-upload]: https://secure.php.net/manual/en/features.file-upload.php
[php.multiple]:
	https://secure.php.net/manual/en/features.file-upload.multiple.php
[tus-node-server]: https://github.com/tus/tus-node-server
[tus]: https://tus.io/